- Hey guys, let me introduce Umut (he just joined the group) - he is
aspiring to be a micro capsule boat adventurer. He doesn't speak
english very well, but he tries really hard.
He is looking to get a boat designed similar to McNally's "Big C".
The voyage he wants to take is from Turkey to Italy, about 1000 miles.
Couple of big problems, the greeks hate turks, so if he is blown to
their lands, they will probably kill him.
He has no sailing experience, but is eager to learn, and lives 20
minutes from a marina. With a hopeful launch date of 1 year from
now, he should have ample time to construct a boat, and learn to sail
it. He is fairly poor, but thinks he can scounge up enough
polyester resin and fiberglass to make a boat like this.
He has caught a lot of flack in the other groups for having no
experience at sailing. Please go easy on him, he is a nice guy -- we
all have to start somewhere, this is the beginning of his journey.
Ah, a trimeron. That's a completely
different animal. I thought you were
talking about a monohull. The outriggers
control the roll.
Yet I agree with the need for a foil,
based on my experiences in light weight
boats in windy conditions. As for
controlling pitch, you could take some
lessons from problems experienced by
maxi-cats like Playstation and their
That looks like fun.
From: "John welsford" <jwboatdesigns@x...>
> Our experiences are pretty diferent, and not
> surprisingly we have come to different
> conclusions. Mine are mostly from fullsized but
> without an accellerometer its hard to be really
> accurate. Seat of pants is notoriously
> The long skinny boat I am doing is a foil
> stabilised blue water power trimaran with a
> cruising speed up around 20 knots, lots of
> interesting hydrodynamic problems with this one,
> control of pitch being only one of the issues.
> John W
> -----Original Message-----
> From: nutty_boats [mailto:nutty_boats@y...]
> Like you, I'm not prepared to argue. My
> observations have been in comparing free
> floating models in the same conditions.
> In those cases, my observations are that
> narrower boats had noticeably lower heave
> than wider boats. It was in that case
> that I made the connection that heave and
> pitch seemed to be connected. I could be
> wrong on the connection, but the
> observation stands on its own.
> Where the difference seems to count most
> is where the period of the waves vary
> between about 1/2 to twice the length of
> a boat. Where the wave period is above
> about 5 times the length of a boat, there
> seems to be very little difference
> between different hull forms (except at
> the very top of the waves, where a wide
> boat presents a greater target for wind).
> Concerning the boat with a L/B ratio of
> 15, I would be really looking for ways to
> reduce roll. While I haven't done any
> model studies, literature searches
> indicate that a long, narrow boat with a
> L/B ratio above 6 seems to roll side to
> side more. My suspicion is that the cause
> of the increased roll may be that the
> ends are long enough that in the right
> conditions, the narrow ends with little
> roll resistance are able to lift up the
> center of the boat where most of the roll
> resistance is found out of the water or
> shallow enough that it has little roll
> resistance. The result is a quick roll.
> How to handle that? There it is harder to
> guess, but I suspect that may be the
> reason for the raised ends with much
> flotation in the dugout canoes used by
> the ocean going Indians along the
> northwest coast of the U.S. and extreme
> west of Canada. Then when the ends raise
> the center out of the water, the center
> is suspended like a hammock between the
> T. Lee.
> --- In email@example.com, "John welsford" <jwboatdesigns@x>
> > I think that we will have to agree to disagree on
> > this one, I've sailed a lot on long and skinny in
> > quite large sizes ( 36 ft x 7ft) as well as short
> > and fat, and dont think that there is any
> > noticeable difference in heave accellerations with
> > hullforms. Pitch yes, roll yes, heave rates are
> > governed by the wave size but the accelleration is
> > almost purely a function of induced displacement
> > change not subject to hull shape.
> > But if you can persuade me, I'm interested as it
> > would lead to some intrigueing possibilities.
> > Incidentally I just contracted to design a boat
> > that has a beam length ratio of 15 / 1 and a
> > displacement to length ratio of around 40 which
> > makes this discussion pretty pertinent.
> > John W